Polymerization of substituted indene



March 9, 1948. F. J. soDAY POLYMERIZATION F SUBSTITUTED INDENE FiledFeb. 12', 1944 lpolymers of alkyl enema Mu. 9, 194sl UNITED 2.437.278 yroLYMEmzATroN or sUs'rI'rU'rEn INDENE Frank J. Soday, Baton Rouge, La.,assignor to The United Gas Improvement Company, a corporation ofPennsylvania Application February 12, 1944, Serial No. 522,094

6 Claims. (Cl. 260-80) l This invention relates to the preparation ofsubstituted indene.

More particularly, this invention relates to the polymerization ofhydrocarbon fractions vcontaining alkyl substituted indene, by means ofa catalyst selected from the group consisting of alkyl and aryl acidsulfates.

Alkyl substituted indenes are unsaturated hydrocarbons, the structure ofwhich may be repref sented by the following formula:

in which at least one f the group consisting of R., R1, R2, Ra, and R4is an alkyl group, such as methyl, ethyl, propyl, butyl,- and/or amylgroup; the remaining-being hydrogen, and n represents the fact that from0 to 4 of ysuch alkyl groups may be present on the benzene ring portionof the indene molecule.

Alkyl substituted indenes occur generally in coal tar and in hydrocarbonfractions obtained in the distillation of coal tar, particularly theunsaturated fractions boiling above the boiling point of indene, namely182 C.

In such fractions, alkyl substituted indene is associated withcoumarone, an oxygen containing unsaturated compound having a structural-formula somewhat similar to indene,

CH it 0/ and/or with one or more substituted coumarones.

Hydrocarbon fractions containing alkyl substituted indene may beutilized for the production of reslnous polymers by effectingpolymerization of the unsaturated constituents of such fractions. In themanufacture of artificial gases such as coal gas, oil gas andcarburetted water gas, considerable quantities of tar are produced andthe gas contains substantial quantities of readily condensablematerials. Alkyl substituted indene may generally be found in thecondensate and in the light oil obtained upon distillation of thesevarious tats. r

2 Fractionation of light oil from coal gas, oil gas or carburetted watergas yields fractions, the higher boiling of which contain largeconcentrations of alkyl substituted indene. One or more pure alkylsubstituted indenes may be obtained from these fractions by furthertreatment using special processes.

Generally speaking, fractions obtained from oil gas or carburetted watergas manufacture do not contain coumarone or substituted coumarone, whilesimilar fractions obtained from coal gas manufacture will contain one ormore of these compounds. The manufacture of oil gas or carburetted Watergas involves the pyrolytic decomposition of petroleum oil as is Wellknown in the art.

In the practice of my invention. I employ one or more alkyl indenes, andparticularly one or more selected from a group consisting of methyl.ethyl and propyl indenes. Excellent results are obtained by the use ofone or more methyl substituted indenes, Mono-alkyl substituted indenes,are frequently preferred.

Such methyl substituted indenes'may be in the form of pure ortechnically or commercially pure form, or in the form of light oilfractions containing any desired proportion of methyl indene.

I prefer to employ light oil methyl indene fractions derived from thepyrolysis of petroleum or of petroleum hydrocarbons in the gaseous phasein the presence of steam at average set temperatures above 1100 F. andmore particularly above 1300 F. in the practice of my invention. Suchfractions are substantially free from coumarone or substitutedcoumarone. f

I prefer to employ such light oil fractionsbolling mainly in the rangeof from to' 220 C. These fractions may be further subdivided, ifdesired, to give fractions boiling mainly in the range of 190 to 200 C.,200 to 210 C., and 210 to 220 C., respectively. v Generally speaking,lthe resinous polymers obtained from such fractions have melting pointswhich increase with'the boiling range of the fraction from which theywere prepared.

A mixture of two or more of such fractions also may be employed in thepractice of my invention, as well as mixtures of one or more methylindenes, or fractions thereof, with indene.

While the methyl indene fractions used in the preparation oi' theresinous polymers described herein may contain any desired proportion ofsuch methyl indenes, I generally prefer to employ fractions containingnot less than 30% andmore particularly not less than 50% -unsaturatedhydrocarbons.

Aikyl substituted indene. or hydrocarbon fractions containingsubstituted indene, may be polymerized to yield resinous materials bycontacting with sulfuric acid. However, the polymerization of alkylsubstituted indene with sulfuric acid is a highly exothermic reactionand is thus very dilcult to control. There is a pronounced tendency forthe reaction temperature to increase at a very rapid rate at certainstages of the polymerization resulting in the production of a relativelylarge proportion of sludge, as well as the production of a dark coloredresin of inferior solubility in the usual solvents.

Furthermore, unduly large losses of reactive material in the form ofsludge results from undesirable side reactions when sulfuric acid isused as a catalyst for alkyl substituted indene polymerization. This isdue to an intense local superheating in various portions of the reactingmaterial during the course of the reaction. The recovery and..purication of the resinous polymers from the polymerized materialobtained under these conditions is an extremely dinlcult undertaking. Inaddition, the resin obtained is frequently of such character as to be oflittle value for many industrial applications such as, for example. thepreparation of coating compositions.

I have found that the polymerization of hydrocarbon fractions containingalkyl substituted indene but substantially free from coumarone and/orsubstituted coumarone, may be effected, and the exothermic nature of thereaction carefully controlled with the production of alkyl substitutedindene resins of unvaryins quality and unusually good properties, by theuse of alkyl, such as methyl, ethyl, propyl, butyl, and amyl; and arylsuch as phenyl. tolyl, xylyl, phenyl methyl, and the like; acid sulfatesas polymerizing catalysts.

Generally speaking, the organic acid sulfates which I have foundeffective for the polymerization of hydrocarbon fractions containingalkyl substituted indene and substantially free from coumarone andsubstituted coumarone may be prepared by the action of sulfuric acid orsulionating agents upon ethers, alcohol, esters, and olefines.

Although alkyl andvaryl acid sulfates suitable for use as alkylsubstituted indene polymerization catalysts may be prepared by any ofthese methods. the use of organic ethers has been found to be aparticularly convenient and advantageous` method for their production.

The reaction products of ethers and sulfuric acid are highly desirableas polymerization catalysts, not only because of their property ofproducing light colored alkyl substituted indene resins of good quality,but also because of their stability. Such catalysts may be stored forrelatively long periods of time without any serious loss of catalyticactivity.

When the alkyl substituted indene polymerization catalysts are preparedfrom organic ethers, various alkyl. aryl-alkyl, and aryl ethers may beused. The choice of the ethers will depend upon a number of factors suchas, for example, ready availability, low cost. convenience in handling,and the like.

Illus tive of alkyl ethers which produce desirable ca ats may bementioned. among others, diethylether and diisopropyl ether, having thefollowing general structural formulae:

C CB: Diethyl ether Diisopropyl other Among the aryl-alkyl ethers whichare suitable for the production of alkyl substituted indenepolymerization catalysts may be mentioned. as examples, anisole andphenetole, having the following general structural formulae:

Anisole Phenetole Illustrative of the aryl ethers which may be reactedwith sulfuric acid to produce desirable alkyl substituted indenepolymerization catalysts may be mentioned. among others, diphenyl oxidehaving the following general structural formulae:

Oro@

Diphenyl oxide In addition to ethers, other organic compounds may bereacted with sulfuric acid to produce suitable catalysts for thepolymerization of alkyl substituted indene.

For example, the reaction of sulfuric acid in alcohols produces alkyl oraryl hydrogen sulfates which are also eifective as alkyl substitutedindene polymerization catalysts. Illustrative of the suitable alcoholsmay be mentioned, among others, ethyl alcohol and isopropyl alcohol.

The reaction products of sulfuric acid andorganic esters such, forexample, as ethyl acetate, methyl acetate, and isopropyl acetate. arehighly satisfactory as alkyl substituted indene polymerizationcatalysts.

Generally speaking, the essential constituent of the catalysts which maybe used for the polymerization of alkyl substituted indene-containinghydrocarbon fractions substantially free from coumarone and/orsubstituted coumarone is an allqrl or aryl acid sulfate. This isgenerally the case regardless of the materials from which such catalystsare prepared. the method of their preparation. or the nature andrelative proportions of any other components with which such catalystsmay be associated.

I'he nature of the alkyl substituted indene-containing fraction to bepolymerized will determine to a large extent the manner in'which thecatalysts will be prepared in order to secure a polyn merization productof the desired quality.

Various methods for the preparation of organic acid sulfates suitablefor the catalysts of alkyl substituted indene polymerization reactionswill be discussed more in detail hereinafter.

'I'he polymerization is preferably carried out by the addition of thecatalysts to the albi substituted indene or mixture containing alkylsubstituted indene, although other methods may be used if desired.

The exact mechanism of the Polymerization of alkyl substituted indene isunknown. It is believed, however, that'the reaction proceeds stepwisc bythe regular addition of successive molecules of the monomer to thedouble bond present at the stage of polymerization immediately pro-Although the process of the present invention is particularly adapted tothe preparation of alkyl substituted indene polymers from hydrocarbonfractions containing alkyl substituted indene and substantially freefrom substituted cournarone, pure alkyl substituted indene and fractionscontaining high concentrations of alkyl substituted indene andsubstantially free from coumarone and/or substituted coumarone may beutilized with the production of desirable resinous products.

In order to insure the production of lightcolored high melting resins,the temperature of the polymerization reaction should be controlledwithin fairly narrow limits.

In general, polymerizing temperatures in the range of to '10 C. arepreferred, and particularly temperatures within the range of to 40 C.

The use of aryl and alkyl acid sulfates as alkyl substituted indenepolymerization catalysts, generally speaking, makes unnecessary anyelaborate external means of cooling the reaction mixture.

The reaction mixture should, however, be cooled during the course of thereaction to prevent the development of excessive temperatures.

Among other ways, such cooling maybe effected by circulating a coolingmedium through cooling coils immersed in the reaction vessel,circulating a cooling medium around the outer surface of the reactionvessel, or the reaction mixture may be circulated through externalcondensers during the course of the reaction.

It is generally desirable to thoroughly agitate the reaction mixtureduring the polymerization process in order to maintain an eventemperature throughout.

Generally speaking, when the material to be polymerized contains a highconcentration of alkyl substituted indene, an inert solvent ispreferably added thereto as a diluent before the addition of thecatalyst.

Solvents suitable for this purpose include hydrocarbon solvents,chlorinated solvents, and other solvents which are not attacked by thecatalyst during the course of the polymerization.

Illustrative of the hydrocarbon solvents may be .mentioned, amongothers, benzene, toluene, xy-

lene, petroleum ether, petroleum naphtha, solvent naphtha and heptane.

Illustrative of chlorinated solvents which may be used as diluents maybe mentioned, among which the purification may proceed in the usual way.In the practice of the process, the polymerization reaction may becarried out batchwlse in suitable containers, or various continuous orsemi-continuous methods may be utilized.

The quantity of alkyl or aryl acid sulfate catalysts which may be usedto effect polymerization of hydrocarbon fractions containing alkylsubstiothers, chloroform, carbon tetrachloride, ethylene dichloride, andchlorobenzene.

The use of such inert solvents is also advantageous after a hydrocarbonfraction containing a high concentration oi.' alkyl substituted indene,such as for example, a pure alkyl substituted indene, has beenpolymerized. The reaction product of such a polymerization, generallyspeaking, is solid or highly viscous and in such case may be relativelydimcult to purify. When it is desired to polymerize substantially purealkyl substituted indene or hydrocarbon fractions containing highconcentrations of alkyl substituted indene, but substantially free fromcoumarone and/or substituted coumarone, suitable solvents such as, forexample, any of the solvents hereinabove enumerated, may be utilized todissolve the solid or highly viscous reaction mas, after ,tuted indene,but substantially free from coumarone, and/or substituted coumarone, isnot critical. Generally speaking, approximately 1 to 10% by volume ofcatalyst based upon the alkyl substituted indene present in the mixtureundergoing polymerization will be found sufficient in most eases,although larger quantities of catalyst may be employed if desired,particularly for the polymerization of fairly dilute solutions.

After the completion of the reaction, the polymerized mixture isgenerally allowed to settle for a short period of time, after which thecatalyst layer may be drained off or removed by other suitable methods.

The remaining traces of catalyst may then he v ious contact materials,such as, for example, clay,`

fullers earth, diatomaceous earth, alumina, silica, or similarmaterials.

Various combinations of these methods may also be employed to remove theremaining traces of catalyst with equally good results.

For example, the polymerized solution may be neutralized with an aqueoussodium carbonate solution, followed by the removal of the water layer,and the application of clay. After the removal of clay, the solutionwill be found to be light in color and completely neutralized.

In general, neutralization with contact agents such as clay may benormally carried out at elevated temperatures, such as for example, toC.

The ease with which the polymerized solutions resulting from thisprocess may be neutralized is a valuable characteristic of the presentinvention.

Thus, when sulfuric acid is used for the polymerization of alkylsubstituted indene in hydrocarbon fractions, the polymerized solution,generally speaking, cannot he completely neutralized by the applicationof clay alone due to the presence of excessive quantities of acid sludgeand sulfonated materials.

However,v when alkyl or aryl acid sulfates are employed as catalysts,under normal polymerizing conditions, the catalyst may be completelyremoved at the end of the polymerizing process by treatment with clay.

The use of alkyl or aryl acid sulfates as catalysts. when polymerizingalkylsubstituted indene according to my present invention, avoids thenecessity of using alkaline solutions to effect neutralization.

Alkaline solutions may. of course, be used, if desired, either alone orin conjunction with the use of other neutralization agents such as clay.

The polymerized solution is preferably distilled in order to removeunpolymerized material, as well as to afford a separation between theliquid polymers, commonly referred to as heavy oil, and the solidresinous polymers. In general, however. only very small quantities ofthe liquid polymers are normally obtained in the practice of myinvention.

The distilling and hardening operations may be carried out in anysuitable manner, such as, for example, distillation under reducedpressure.

Steam distillation, using either saturatedor superheated steam, may alsobe employed in the distilling and hardening operations with excellentresults, especially when carried out under reduced I pressure.

The alkyl substituted indene resins obtained as a result of the processoutlined herein are, generally speaking, light in color, compatible-with varnish oils and the usual solvents, and have melting pointsranging from room temperature, or even below, to 100 C., or higher.-They may be used for the preparation of oil varnishes, spiritvarnishes, paints, lacquers, enamels, and coating compositions ingeneral. They have excellent water and alkali resistance and can be usedto advantage for applications requiring .a coating with good dielectricproperties.

For many uses, resins having melting points above, say, 40 C. arepreferred. Such resins may l' be prepared by the use of temperatures inthe lower range previously indicated, such as below 409 C.

Generally speaking, also, resins having melting points above 40 C. maybe obtained by the poly-V merization of alkyl substituted indenefractions containing at least 50% unsaturated hydrocarbons.

One exemplary method for carrying out the process may be to proceed in.a semi-continuous' manner, starting initially with the formation of theorganic acid sulfate catalysts, and proceeding through thepolymerization of the alkyl substituted indene to the separation of theliquid and solid polymer products.

Such a procedure is diagrammatically illustrated in' the accompanyingfigure, wherethere is shown apparatus for the production of an organicacid sulfate catalyst, and connected therewith, apparatus for thepolymerization of hydrocarbon fractions containing alkyl substitutedindene, apparatus for the neutralization and purification of thepolymerized'reaction product, and 'apparatus for the separation ofthe'various polymer 'products thus produced.

Coming now to the initial step in such a procedure, namely that ofpreparing the catalyst, it has been pointed out above that oneconvenient method, among others, for the preparation of alkyl or arylacid sulfate catalyst is to react sulfurlc acid with an organic etherselected from the class consisting of alkyl, aryl-alkyl, and arylethers.

While this reaction may be carried out in any desired manner, apreferred method comprises mixing the desired ether with the sulfuricacid at room temperature, followed by heating to a temperaturesuiliciently high to promote the reaction betwecn the sulfuric acid andthe ether. The temperature, however, should not be increased to such apoint as to cause any appreciable decomposition of the ether or thesubstituted sulfuric acid catalyst subsequently obtained.

The proportions of acid and ether used in the preparation of thecatalyst may be varied over very wide limits, the properties of theresulting oi' acid to approximately one mol. or slightly less, of ether.v-

An alkyl substituted indene polymerization catalyst prepared in thismanner may be stored for relatively long periods of time without anyserious loss of its catalytic activity.

While the exact nature of the reaction by which the alkyl substitutedindene polymerization catalysts herein described are'formed, by theaction of the sulfuric acid upon organic ethers, has not been definitelydetermined, the following is offered as a possible explanation.

An ether, such, for example, as diethyl ether is believed to rst reactwith the sulfuric acid to form ethyl hydrogen sulfate and ethyl alcohol.

Sulfuric acid is then believed to react with the ethyl alcohol to formadditional quantities of f ethyl hydrogen sulfate, together with anequi- These reactions indicate the products which are believed obtainedwhen mixtures containing prodifferent properties.

catalyst depending in part on the proportions I In general, it may besaid that the activity of the catalyst will depend upon the quantity ofacid used in the preparation of the catalyst relative to the quantity oforganic ether employed.

It is important to control the activity oi' the polymerization catalystprepared in order to control the exothermic polymerization reaction. Itwill be appreciated that catalysts containing free sulfuric acid will,in general, bring about a polymerization reaction with a rapid evolutionof heat.

For example, the use of larger quantities of acid than those shown aboveresults in the production of a catalyst which consists essentially of amixture of sulfuric acidand alkyl and/or Aaryl acid sulfatos. Thiscatalyst, because of its sulfuric acid content, will be more active thanthe catalyst previously described when used for the polymerization ofalkyl substituted indene or hydrocarbon fractions containing alkylsubstituted indene. l

The use of smaller` quantities of acid results in the production of acatalyst containing either free alcohol or ether, or both, dependingupon the ratio of the reactants employed and the con. ditions underwhich the catalyst was prepared, such as, for example, the temperatureand the length of the reaction.

In general, a catalyst produced in this manner is somewhat less activethan a catalyst produced by the reaction of two mols` of acid with onemoi of ether,

Similar reactions occur in the case of 'other alkyl or aryl ethers whichmay be used for the production of alkyl substituted indenepolymerization catalysts.

For example, when an ,alkyl substituted indene polymerization catalystis prepared through the reaction of sulfuric acid with an alkyl-arylether, the resulting catalyst comprises a mixture of alkyl acid sulfateand aryl acid sulfate, i1' the reaction is carried to completion. Thisis shown in 9 the following reaction, in which phenetole is reacted withsulfuric acid.

cmocmcm-i-msol ctmnsoiwmcmon CHaCHrOH-l-HzSOrCHaCHaHSOi-l-HIOSubstituted ethers may, if desired, be used in place of ordinary etherswith equally good results. For example, dichlorodiethyl ether may bereacted with sulfuric acid to give asuitable catalyst.

Although reference has been made more specliically to the use of organicethers for the production of alkyl substituted indene polymerizationcatalysts, it is to be understood that these materials have beenreferred to as illustrative examples only, and the organic acid sulfatosprepared in other ways, such, for example, as the reaction of sulfuricacid with oleflnes, alcohols and esters, may additionally be used aseffective polymerization catalysts for alkyl substituted indene.

In the diatic flow sheet of the following drawing, Il represents areaction vessel in which the polymerization catalyst may be prepared.Sulfuric acid from the storage tank I2 and an organic ether from storagetank i3 may be added to the reaction vessel il through lines i4 and Ilrespectively controlled by valves I5 and i1 respectively. 'I'hereactants may be thoroughly agitated by means of stirrer I3, if desired.

The reaction vessel I I is provided with a heating and cooling chamber|9gwlthin which there may be circulated heating or cooling medialintroduced through lines 20 and withdrawn through lines 2|.

Generally speaking, the reactants for the preparation of the alkylsubstituted indene polymerization catalysts are preferably initiallycontacted atroom temperature, after which they are preferably heated toa temperature between 50 and 100' C. to eiIect the reaction. For thispurpose, it may be necessary or desirable to initially flow coolingliquid through the chamber Il while mixing the reactants, and thereafterflow a heating liquid through chamber I9 in order to eifect reaction ofthe sulfuric acid and the organic ether.

Line 22 connects the reaction vessel in which the catalyst may beprepared, with the polymerizing vessel. The alkyl substituted indene orthe hydrocarbon fractions containing alkyl substituted indene to bepolymerized are preferably added to the polymerizing vessel prior to theaddition of the catalyst, though this is not essential.

Line 22 is provided with valve 23 in order that the rate of addition ofthe catalyst to the alkyl substituted indene fractions contained in thepolymerizing vessel 24 may be controlled. 'I'he charge stock for thepolymerizing vessel 24 may be supplied thereto from storage tank 25through the feed line 25 controlled by valve 21.

As has been mentioned, when pure alkyl substituted indene or ahydrocarbon ,fraction containing a high concentration of alkylsubstituted indene is employed, it is generally advisable to add theretoa solvent as a diluent. The solvents may be added to the polymerizingvessel from the solvent storage tank 28 through feed line 29 controlledby valve 30. i

The polymerizing vesselV 24 may be equipped with a stirrer or otheragitating means, 3|, and a heating and cooling chamber 32. 'I'he heatingor cooling chamber 32 may be equipped with feed line 33 and withdrawalline 34 for the circulation therethrough of heating and cooling liquids.

In carrying out the polymerization reaction. the desired quantity ofalkyl substituted indene. or a hydrocarbon fraction containing alkylsubstituted indene may be withdrawn from its storage tank 25 andintroduced into the polymerizing vessel 24 followed by the addition ofsolvents. if desired, from the solvent storage tank 25. The alkyl oraryl acid sulfates, or mixtures containing one or both of these, maythen be slowly added to the material in the polymerizing vessel 24. Thetemperature should be maintained at a suitable temperature, such as 20to 30 C., during the course of addition. 1

'I'he reaction is preferably continued for an additional period oi' timeto insure the desired degree or polymerization, the temperature beingmaintained within a suitable range, such as 20 to 30 C. during thereaction period. l'Ihe `mixture is preferably continuously agitatedduring the course oi' the reaction, for example, by means of the stirrer3|. After the completion of the reaction, the mixture may be allowed tosettle after which the spent catalyst and sludge may be removed, forexample, by means of lines 34 and 35 controlled by valve 36.

The polymerized solution may then be transferred to the neutralizing anddrying vessel 31 through lines 34 and 38, controlled by valve 3l. A pump40 may be introduced in line 38, if desired, to transfer the polymerizedproducts to the neutralizing and drying vessel 31.

In the neutralizing vessel 31 the polymerized mixture may be neutralizedby means of an aqueous alkaline solution, or clay, or by combination ofthese methods. If a neutralizing agent is employed, it may be added tothe neutralizing and drying vessel 31 from the storage tank 4I throughline 42 controlled by` the valvel 43. If clay is utilized to effect theneutralization of the polymerized solution, the clay may be added tothev neutralizing or drying vessel-31 from storage tanks 44 through line45 controlled by sliding valves 43 and 55, or in any other suitablemanner, as desired.

The neutralizing and drying vessel 31 may be equipped with a stirrerorother agitating means 41, and with a heating and cooling chamber 43, ifdesired, through which may be circulated heating and cooling liquidsintroduced through line 49 and withdrawn through line 50.

After the neutralization of the polymerized solution has been completed,any aqueous solution which may have been added may be removed throughthe lines 50 and 5| controlled by valve 52. The neutralized solutioncontaining the alkyl substituted indene polymers may then be dried, ifdesired, by the application of lime stored in storage tank 53 and addedto the vneutralizingand drying vessel in any suitable manner such as,for example, through line 45 controlled by sliding valves 54 and 55. f

The further drying of the polymerized mixture may be omitted if desired.

The polymerized mixture may then be ltered by any suitable means, such,for example, as by forcing it through a suitable lter pressy 56 by meansof a pump 51 inserted in lines 50 and 53. the latter preferablycontaining a valve 59 for controlling the rate of flow of thepolymerized mixture to the filter press.

After ltering, the polymerized solution may be delivered to hardeningvessel 60 by means of line 5i. In the hardening vessel the solvent andoily by any desired method.

In the diagrammatic now sheet the separation of the oily polymers andthe solvents from the solid polymers is diagrammatically shown as beingeffected by distillation although other suitable methods may beemployed.

The hardening vessel 60 may be equipped with a stirrer or agitatingmeans 82, and with a heating or cooling chamber 62 through which may becirculated heating or cooling liquids introduced through lines 83 andwithdrawn through line 64. Steam may be introduced into the hardeningvessel l by means of the line 85 controlled by valve Il. this linepreferably extending nearly to the bottom of the hardening vessel andterminating in the distribution ring 81.

After introduction oi' the polymerized solution into the hardeningvessel 80, it may be rst distilled by the application of heat suitablyunder reduced pressure maintained by means of vacuum line 0l connectedto a vacuum pump not shown. The vapors may be passed from the hardeningvessel l0 into the distilling column 69 through line 1l and thereafterthrough condenser 1i connected to the distilling column by lines 12 and13. The return lines 1I may be equipped with a control valve 1l.

The condensed vapor products may be collected in the liquid productreceivers 15, connected to the condenser by means of line 16 anddistributing means 'l1 controlled by valves 18.

After the removal of the desired quantity of liquid products from thepolymerized mixture contained in chamber 60, steam may be introducedinto the hardening vessel through line 65 and distributing means 81 toremove heavy oils. The residual polymerized mixture remaining after thehardening operation may then be transferred to the resin pan 19 throughline 80 controlled by valve Il. and allowed to harden into the desiredresinous polymer in pan 19. Valve 8| should preferably be positionedwithin the heating or cooling chamber 82.

Although there has been described the production of alkyl substitutedindene polymers by a somewhat specific process, it is to be understoodthat this has been illustrative only of the general nature of thisinvention and is not in any sense a limitation thereof.

For example, the alkyl and aryl acidsulfates may be prepared in anyother desired manner, and at any desired temperature and in any desiredproportion.

Hydrocarbon fractions containing any desired concentration of one ormore alkyl substituted indene may be employed, and the use of a solventas a diluent may or may not be utilized as desired.

Any desired neutralization agent or other ma.- terials for removingexcess acid from the catalyst may be employed in any manner as desired,and other methods of effecting removal of water from the polymerizedproduct may be used.

Filtration of the polymerized product may be accomplished in any mannerfound desirable, and the resultant polymers may be puried and separatedby any convenient method.

v".l'l'ie following examples will further serve to exemplify the processfor the polymerization of alkyl substituted indene and for thepreparation of alkyl substituted indene polymerization catalystssuitable for use in the herein described polymerization processes.

Example I Approximately 20 parts by volume of sulfuric acid is slowlyadded to approximately`80 parts 12 i by volume of dilsopropyl ether withthoroug agitation. The temperature of the reaction mixture is maintainedbelow 50 C. by circulating a cooling medium around the outer surfaces ofthe reaction vessel.

A quantity' of 60% methyl indene fraction boiling mainly in the range of190 to 200 C. and equivalent to approximately 10 times the volume ofcatalyst mixture, prepared from sulfuric acid and diisopropyl ether. isthoroughly mixed with an equivalent volume of xylene as a diluent, andthe mixture cooled to a temperature of approximately 25 to 30 C. To thismixture there is added the catalyst slowly and with vigorous stirring.The temperatureof the reaction mixture is maintained at approximately 30C. throughout the entire reaction by circulating a cooling mixturearound the outer surfaces of the polymerizing vessel.

After a period of approximately five hours, the polymerized solution istransferred to a neutralizing and drying vessel where the catalyst isneutralized by the addition of a 20% solution of sodium hydroxide.Additional solvent is added to the neutralized solution. after which itis well washed with water and driedover lime.

The solvent and unpolymerized material is removed by distillation at atemperature of 200 C. and under a reduced pressure of approximately 20mm. of mercury, absolute. after which the residual mixture istransferred to a resin pan and allowed to harden.

There is obtained a light-colored methyl indene resin, soluble in theusual solvents and compatible with varnish oils.

Example II Boiling range-zoo-zw c. Unsaturated hydrocarbon content=65%weight as determined by bromine titration;

is mixed with approximately 500 parts by volume yof high-flash petroleumnaphtha in a polymerizing vessel equipped with a stirrer. To thismixture, there is slowly added with thorough agitation a catalystprepared by reacting 50 parts by volume of sulfuric acid withapproximately 45 parts by volume of diethyl ether. The polymerization isallowed to proceed at a temperature between 20 and 25 C., maintainedwithin this range by circulating a cooling medium around the outersurfaces of the polymerizing vessel. The temperature control andcontinual agitation is utilized. to prevent any sudden temperaturesurges within the polymerizing mixture.

The polymerization is allowed to proceed for a period of approximatelyfive hours, after which the catalyst is removed therefrom and theremaining polymerized solution transferred to a neutralizing and dryingvessel.

In the neutralizing and drying vessel approximately parts of fullersearth is added to the polymerized mixture. It is then heated to atemperature of approximately 100 to 110 C.,

13 Example IIIv Approximately '100 parts by volume of a 60% unsaturatedhydrocarbon fraction containing methyl indene and boiling mainly in therange of 21o-220 C. is mixed with approximately 500 parts by volume ofpetroleum spirits in a polymerizing vessel provided with an agitator andan external temperature control jacket. To this mixture is slowly addedwith constant stirring an organic acid sulfate catalyst prepared byreacting 30 parts by volume of sulfuric acid with 40 parts by volume ofdiisopropyl ether. The polymerization reaction is maintained at atemperature'of 30 C., or less, by circulating a cooling medium aroundthe outer surfaces of the polymerlzing vessel.

The polymerization is allowed to proceed for a period of approximatelythree hours, after which the spent catalyst is removed. Fuller's earthis then added to the polymesized mixture. It is then heated to 100 to110 C. for a period of approximately 30 minutes and subsequentlyfiltered.

From the polymerized solution, the indene resin is obtained by removingthe solvent by steam distillation. AThe resinous polymer thus obtainedis very light colored and is readily compatible with the usual dryingoils.

Illustrative of methods for preparing organic acid sulfates, suitable ascatalysts for the polymerization of substituted indene, are given thefollowing examples:

Example IV Fifty parts by volume of 96% sulfuric acid was slowly addedwith constant agitation to approximately 45 parts by volume of diethylether in a reaction vessel provided with an agitator and a temperaturecontrol jacket.

The temperature of the mixture of sulfuric acid and diethyl ether wasmaintained below 30 C. until the entire mixture had been thoroughlyagitated and mixed.

Reaction between the sulfuric acid and the diethyl ether was eil'ectedby heating the mixture of these reactants to a temperature ofapproximately '70 C. for a period of approximately one hour. I'hisheating was effected by introducing a-heating medium in the temperaturecontrol jacket surrounding the reaction vessel.

The resultant catalysts, comprising ethyl hydrogen sulfate and water,are extremely effective and desirable catalytic agents for thepolymerization of alkyl substituted indene.

Example V 'I'hirty parts by weight of 66 Baum sulfuric acid was slowlyadded with constant stirring to approximately 40 parts of diisopropylether. During the mixing of these materials the temperature wasmaintained at or below 30 C. After the reactants had been thoroughlymixed, the mixture was heated to a temperature of approximately 60 C.for a period of approximately three hours.

The resultant organic acid sulfate is an excellent catalyst for thepolymerization of alkyl substituted indene. and possesses highpolymerizing activity even after storage for a relatively long period oftime.

Alkyl substituted indene polymers prepared by the process hereindescribed possess properties which make them particularly adapted tomany industrial applications. Because the polymerization of alkylsubstituted indene may, by the proc- 14 ess herein described, beeffected under relatively low temperature conditions, theresultantpolymer is, generally speaking, found to be clear and free from color.Additionally, polymerized solutions free of acid sludge are obtained,thus resulting in greater yield of the desired alkyl substituted indenepolymer.

Illustrative of the many applications of alkyl substituted indenepolymers prepared by the process herein described, may be mentioned theuse of such polymers in coating composition formulations, particularlyin the preparation of varnishes.

Illustrative of the use of an alkyl substituted indene polymer preparedby the herein described process, is given the following illustrativeexamples.

Example VI A mixture of twelve parts of methyl indene resin and 14 partsof tung oil was heated to a temperature of approximately 400 F. during aperiod of approximately 20 minutes. This mixture was then heated to atemperature of approximately 560 F. during a period of ten minutes andheld at this temperature for an additional period of three minutes. Itwas then allowed to cool to 535 F., held at this temperature for aperiod of six minutes, and then chilled to a temperature of 400 F. Atthis temperature 26 parts of naphtha was added to reduce the varnishmixture, and thereafter the mixture was allowed to cool to roomtemperature.

To the varnish mixture thus prepared, a desired quantity of drier wasadded at room temperature. v V

'I'he varnish thus obtained was a highly desirable protective coatingcomposition. Coating films prepared from this varnish had unusually goodalkali resisting properties.

In place of tung oil, other drying oils may be employed in thepreparation of substituted indene resin varnishes. These include linseedoil, isomerized linseed oil, oiticica oil, perilla oil, soya bean oil,fish oil, and the like.

The drlers which may be employed include cobalt, lead, and/or manganesesalts of high molecular weight organic acids, such as the naphthenicacids.

While representative procedures for the preparation of alkyl substitutedindene hydrocarbon fractions containing alkyl substituted indene, andfor the preparation of organic acid sulfate catalysts utilized in saidpolymerization processes, have been particularly described, it is to beunderstood that these are by way of illustration only. Therefore,changes, additions, substitutions, and/or modifications may be madewithin the scope of the claims without departing from the spirit of theinvention.

I claim:

l. A method of producing resinous polymer from methyl indene whichcomprises contacting said methyl indene with a catalyst selected fromthe group consisting of alkyl and aryl acid sulfates at a temperature inthe range of 0 to 70 C. in the substantial absence of coumarone.

2. A method for the polymerization of a light oil methyl indene fractionboiling mainly in the range of from to 200 C. and being substantiallyfree from oxygenated compounds which comprises contacting said fractionwith a catalyst selected from the group consisting of alkyl and arylacid sulfates at a temperature in the range of 0 to 70 C.

3. A method for the polymerization of a light oil methyl indene fractionboiling mainly in the range of from 200 to 210' C. .and beingsubstantially free from oxygenated compounds which comprises contactingsaid fraction with a. catalyst selected from the group consisting ofalkyl and aryl acid sulfatos at l temperature in the range of 0 to 70 C.

,4. The resin resulting from the process of claim 1.

5. 'I'he resin resulting from the process ofv claim 2.

6. The resin resulting from the proeess oi claim 3.

FRANK J. SODAY.

REFERENCES CITED The following references are of in the file of thispatent:

UNITED STATES PATENTS Number Name Dato 2,047,245 Anderson July 14. 19382,047,246 Anderson July 14, 1930 2,047,247 Anderson July 14, 19382,092,999 Anderson -L Sept. 14, 1987 2,338,229 Caplan Jan. 4, 19442,344,676 Cline Mar. 21, 1944 2,344,026 Cline Mar. 14, 1944 2,315,771Cline Apr. 8, 1942

